Tow line accumulator



July 14, 1970 P. R. HEFLER TOW LINE ACCUMULATOR Filed March 21, 1968 5 Sheets-Sheet l R wk INVENTOR PAUL R. HEFLER WKM A TTORN'YS Q o o \50 P. RQ HEFLER 'TOW LINE ACCUMULATOR Jul 14, 1575 3 Sheets-Sheet 5 Filed March 21, 1968 INVENTOR PAUL R. HEFLER A T7'0RNEYS United States Patent "ice 3,520,255 TOW LINE ACCUMULATOR Paul R. Heller, Easton, Pa., assignor to SI Handling Systems, Inc., Easton, Pa., a corporation of Pennsylvania Filed Mar. 21, 1968, Ser. No. 715,081 Int. Cl. 1361b 13/00 U.S. Cl. 104-472 9 Claims ABSTRACT OF THE DISCLOSURE A tow line accumulator is provided having chain channels coupled to a transversely movable plate. Movement of the plate causes the chain pusher dogs to lose contact with the tow pin on a vehicle whereby the vehicle will come to a stop at the accumulator.

The present invention relates to an accumulator for use in a tow line. A tow line system having vehicles mounted for movement along a main slot by means of a chain contacting a tow pin on the vehicle is well known. For example, see U.S. Pat. 2,619,370. It is desirable to provide areas along a portion of the main slot wherein the vehicles will accumulate and come to a stop. Such areas may be the loading or unloading areas of the vehicles. Heretofore, such accumulation areas have been provided by causing the conveyor chain to move downwardly so as to lose contact with the lower end of the tow pin.

In some environments, such as on the second or third floor of a building, there is insuflicient room for the tow chain to move downwardly so that it will lose contact with the tow pin. The present invention is directed to an accumulator which is sufiiciently shallow in depth so that it may be utilized on multi-story buildings or warehouses and yet provide for the desired accumulation of vehicles. In accordance with the present invention, the tow line accumulator is provided with a horizontal slide plate which is movable sideways so as to move the chain sideways out of contact with the tow pin. The accumulator of the present invention is capable of being selectively operated from remote areas and is constructed so that the components thereof will automatically resume their original position so that a stopped vehicle may again be coupled to the conveyor chain automatically. The present invention has the added advantage of being selective as to the vehicles which will accumulate.

It is an object of the present invention to provide a novel tow line accumulator.

It is another object of the present invention to provide a tow line accumulator which is responsive to the tow pin and utilizes the pulling force acting on the tow pin to shift the conveyor chain sideways so as to lose contact with the tow pin.

It is another object of the present invention to provide an automatic tow line accumulator which can be operated from a remote position without requiring any motors to effect accumulation.

It is another object of the present invention to provide a novel tow line accumulator which is selectively reliable and automatic.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalties shown.

FIG. 1 is a top plan view of the accumulator of the present invention.

FIG. 2 is a view similar to FIG. 1 but showing the 3,520,255 Patented July 14, 1970 components in a shifted position wherein the chain will lose contact with the tow pin and cause the vehicle to accumulate.

FIG. 3 is a sectional view taken along the line 3-3 in FIG. 2.

FIG. 4 is a sectional view taken along the line 44 in FIG. 3.

Referring to the drawing in detail, wherein like numerals indicate like elements, there is shown in FIG. 1 a tow line accumulator of the present invention designated generally as 10. Accumulator 10 is mounted in a reference surface such as floor 12. Floor 12 has a main slot with portions thereof designated as 14 and 16. Portions 14 and 16 are interconnected by the accumulator which has a slot forming a continuation thereof.

The accumulator 10 includes a housing having a bottom wall 18, side walls 20 and 22 supported thereon, and end walls 24 and 26 extending between side walls. A cover 28 is provided for the housing. Cover 28 is formed in two halves with the halves spaced from one another so as to define the slot which forms a continuation of slot portions 14 and 16.

The entire height of the accumulator as shown in FIGS. 3 and 4 may be six inches or less. The tow pin 30 on the vehicle (not shown) extends into the slot portions 14 and 16. As the tow pin moves along the slot 29 defined by the halves of the cover 28, tow pin 30 contacts the cam surface 32 on a retarder bar 34. Retarder bar 34 is adapted to pivot about pin 36. As shown more clearly in FIG. 3, the pin 36 is surrounded by a bushing mounted in the upper end of a pipe 38. Contact between pin 30 and surface 32 causes the bar 34 to rotate in a clockwise direction in FIG. 1.

There is provided a lug 40 on the lower surface of retarder bar 34. Lug 40 contacts a drive link 42 and causes the same to rotate in a counterclockwise direction in FIG. 1. Link 42 is secured to a pin 44. Pin 44 is mounted in a bushing at the upper end of a pipe 46. Bar 34 and link 42 are coupled together by spring 48.

Link 42 is provided with a lug 43 on its lower surface as shown more clearly in FIG. 3. A slide place 50 is mounted for movement transversely of the guide slot. On plate 50, there is provided a solenoid 52 having its plunger coupled to a block 54. Block 54 is mounted between studs 56 and 58 on plate 50. Lug 43 contacts block 54 on the same side as lug 58. Block 54 is spring-biased to the position shown in FIG. 1 by spring 60. One end of spring 60 is anchored to plate 50.

The plate 50 is slidably supported by a plurality of parallel guide rails 62 fixedly supported on the bottom wall 18 of the housing. Rails 62 are sufiiciently rigid so as to absorb any shock imparted to plate 50 due to contact between tow pin 30 and limit stop 55. Plate 50 is biased to the position shown in FIG. 1 by coil springs 64 extending between plate 50 and side wall 20. The location of the plate 50 in the position shown in FIG. 1 is detected by microswitches 66 and 68.

The chain having pusher dogs 82 at spaced points therealong is adapted to move in a guided path defined by tracks or channel sections 70, 72, 74, 76, and 78 as the chain enters through holes in the end walls of the housing and moves through the accumulator 10. Channel sections 70 and 72 are pivotably interconnected together. The other end of section 72 is pivotably coupled to the slide plate 50. Channel section 74 is firmly supported by plate 50. One end of channel section 76 is pivotably coupled to plate 50. The other end of section 76 is pivotably coupled to section 78.

The return portion of the endless conveyor chain 80 also passes through the accumulator 10. The corresponding channel sections for the return portion are indicated with corresponding primed numerals. It is desirable to have the return portion of the endless chain 80 pass through the accumulator so that there will automatically be facilitated compensation for movement in the chain as will be explained hereinafter.

The operation of the accumulator 10 is as follows:

It will be assumed that it is desirable to cause the vehicle connected to tow pin 30 to accumulate. As the tow pin 30 engages the cam surface 32, it rotates the bar 34 in a clockwise direction in FIG. 1. Contact between lug 40 and link 42 causes the link 42. to rotate in a counterclockwise direction in FIG. 1. This stretches spring 48. Likewise, contact between lug 43 and block 54 causes the entire slide plate 50 to shift from the position shown in FIG. 1 to the position shown in FIG. 2. This causes the spring 64 to be compressed.

As shown more clearly in FIG. 2, channel sections 72 and 76 have pivoted from a straight line position to a position angled with respect to sections 70 and 78. Section 74 is fixedly secured to the plate 50 and moves therewith. At the same time, the sections 72' and 76 for the return portion of the chain have straightened out to thereby provide the slack in the chain necessary to facilitate sideways movement of the chain 80 whereby the pusher dog 82 will lose contact with the tow pin 30. The tow pin 30 will come to a stop when it contacts limit stop 55 fixedly secured to the plate 50.

The above movement of the components is efiected entirely by and is responsive to the tow pin 30. The force necessary to shift plate 50 and compress springs 64 results from the driving force on the tow pin imparted by the pusher dog 82. The components remain in the position shown in FIG. 2 so long as the tow pin 30 remains in contact with the bar 34, bar 34 remains in contact with link 42, and link 42 remains in contact with block 54.

Whenever it is desired to cause the vehicle to continue movement along the slot, it is only necessary to activate solenoid 52 from any remote position. The fact that tow pin 30 is stationary at the accumulator 10 can be ascertained from a remote point by the fact that microswitch 68 is inactive due to having lost contact with the plate 50. Microswitch 68 may be coupled to any suitable indicator. When it is desired to cause the tow pin 30 to continue movement along the slot, solenoid 52 is activated to cause its plunger to withdraw the block 54 against the pressure of spring 60. In doing so, lug 43 loses contact with block 54.

When this occurs, springs 64 expand and shift the plate 50 to the position shown in FIG. 1. The next pusher dog 82 on the chain 80 which enters the accumulator 10 will contact the tow pin 30 and continue to propel the same along the slot. Meanwhile, spring 48 will cause bar 34 and link 42 to assume the position shown in FIG. 1. Also, spring 60 will contract and return the block 54 to the position shown in FIG. 1.

If it is desired that the particular vehicle not stop at the accumulator 10, it is only necessary to activate the solenoid 52. Activation of solenoid 52 withdraws the block 54 so that it cannot be contacted by lug 43 on link 42. Hence, the movement of the tow pin 30 through the slot 29 will merely cycle the bar 34 and link 42 without causing any shifting of the plate 50. Hence, accumulation is selectively controllable.

As pointed out above, no motors as such as required to initiate transverse movement of slide plate 50 to effect accumulation. Hence, the accumulator 10 may be located in remote areas where motors are not capable of being operated due to a lack of motive power. The accumulator 10 is shallow and hence can be more readily located in a variety of areas which will not accommodate depression of the chain to elfect accumulation. Also, when it is desired to re-effect contact between the tow pin and the conveyor chain, the vehicle need not be pushed or otherwise moved. Such contact is attained by the next pusher dog merely by operating the solenoid 52. It will be apparent that the housing for the accumulator is provided with flanges adjacent its upper edge so as to removably support the halves of the cover 28 and that the moving parts are sufficiently spaced above the bottom wall 18 so as to accommodate a substantial amount of dirt and debris which will invariably enter the housing through the slot 29.

It will be apparent from the above that bar 34 is a retarder bar. Hence, bar 34 absorbs kinetic energy from the tow pin 30 to control deceleration gradually so long as it contacts the tow pin 30.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

It is claimed:

1. A tow line accumulator comprising a housing adapted to be mounted in a floor, said housing having a slot adapted to form a continuation of a main slot in the floor, said housing having channels for a conveyor member having pusher dogs adapted to contact a tow pin on a vehicle and push the vehicle along the slot, said conveyor member moving in said channels with said pusher dogs secured thereto, movable means in the housing responsive to contact with a tow pin moving along the housing slot for shifting the channels sideways a sufficient distance so that the conveyor pushing dog can lose contact with the tow pin, and means for causing the channels to return to their original position wherein it is desired to recouple the conveyor to the tow pin.

'2. An accumulator in accordance with claim 1 wherein said movable means includes a contact bar having a contact surface extending across the path defined by the housing slot so that it may contact the tow pin moving along the housing slot, said bar being coupled to a slide plate supported for movement transverse to the housing slot, a portion of said channel being supported by said slide plate.

3. An accumulator in accordance with claim 1 wherein said last-mentioned means is an electro-mechanical device selectively operable from a remote position.

4. An accumulator in accordance with claim 1 wherein said movable means includes a first pivotable member adapted to be contacted by the tow pin, a second pivotable member adapted to be contacted by the first member, a slide plate supporting a portion of said channel, and selectively operable means interconnecting the second pivotable member and slide plate.

5. An accumulator in accordance with claim 1 wherein the channel of said housing includes two generally parallel sections coupled to said movable means so that one section is in a straight line position while the other section is in a position wherein the dog will not contact a tow pm.

6. A tow line accumulator comprising a housing having a slot in its top wall, channel sections within said housing adapted to receive a tow line chain capable of pushing a tow pin along the slot, adjacent ones of said channel sections being pivotably coupled together, a movable member in said housing and having a portion over the chain, and means for moving the channel sections sideways in response to contact between said movable member and a tow pin extending downwardly through said slot and moving along the slot.

7. An accumulator in accordance with claim 6 wherein said means includes a link and a slide plate, said link being coupled to said movable member and slide plate, spring means biasing the slide plate to a first position, movement of the channels sideways compressing the spring means, and selectively operable means interconnecting said slide plate and link, whereby operation of the selective- 5 ly operable means enables the spring means to move the slide plate.

8. An accumulator in accordance with claim 6 wherein said means includes an electro-mechanical device which is selectively operable for interfering with sideways movement of the channels notwithstanding contact between said member and a tow pin.

9. An accumulator in accordance with claim 6 wherein said movable member is a pivotally mounted retarder bar for absorbing kinetic energy from the tow pin so that it can slow down to a gradual stop, said bar having position wherein it projects into a vertical plane containing the slot at an acute angle with respect to the slot.

References Cited UNITED STATES PATENTS 974,599 11/1910 Reynolds 104-172 X 3,011,456 12/1961 Lyons l04172 3,045,610 7/1962 Klamp 104-172 X GEORGE E. A. HALVOSA, Primary Examiner US. Cl. X.R. 

